CN107833195A - The in-orbit dark weak signal target optical imagery Enhancement Method in ocean - Google Patents
The in-orbit dark weak signal target optical imagery Enhancement Method in ocean Download PDFInfo
- Publication number
- CN107833195A CN107833195A CN201711193771.7A CN201711193771A CN107833195A CN 107833195 A CN107833195 A CN 107833195A CN 201711193771 A CN201711193771 A CN 201711193771A CN 107833195 A CN107833195 A CN 107833195A
- Authority
- CN
- China
- Prior art keywords
- image
- ocean
- enhancement method
- orbit
- target optical
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 52
- 230000003287 optical effect Effects 0.000 title claims abstract description 28
- 238000003384 imaging method Methods 0.000 claims abstract description 18
- 230000005540 biological transmission Effects 0.000 claims description 25
- 238000004422 calculation algorithm Methods 0.000 claims description 24
- 238000011084 recovery Methods 0.000 claims description 19
- 238000013178 mathematical model Methods 0.000 claims description 15
- 238000001514 detection method Methods 0.000 abstract description 10
- 230000004888 barrier function Effects 0.000 abstract 1
- 239000000284 extract Substances 0.000 abstract 1
- 230000008447 perception Effects 0.000 abstract 1
- 230000002708 enhancing effect Effects 0.000 description 6
- 238000004088 simulation Methods 0.000 description 5
- 230000001965 increasing effect Effects 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 2
- 238000005457 optimization Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000007123 defense Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T5/00—Image enhancement or restoration
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
Abstract
The present invention relates to the dark weak signal target optical imagery Enhancement Method in in-orbit ocean, enter imaging characteristic modeling first, then detector is collected into the Weak Information from target, scene information is estimated by the method for minimizing constraint, and extracts its phase property so as to which target and Sea background be distinguished；It is difficult to the technical barrier detected in solution Traditional photovoltaic detection method to ocean extremely weak target, it this approach enhance the dark weak signal target feature in ocean, suppress sea clutter and noise of detector simultaneously, breach computation complexity limitation, it is expected to realize the ocean weak signal target detection and identification of big breadth in real time on star, there is important application value；Perception and early warning ability of this method to ocean weak signal target simultaneously, has important value, and this method can be used for marine resources detection, marine resources development etc..
Description
Technical Field
The invention relates to an on-orbit ocean dark and weak target optical image enhancement method, and belongs to the technical field of on-orbit ocean target detection and image quality improvement of a space camera.
Background
The current detection of ocean weak targets is in the hot field, but is quite difficult, and is also very important for maintaining national defense safety, the bottleneck problem is concentrated on that underwater moving targets have strong stealth capability, and the energy radiated by the targets through the sea surface background under the strong clutter is very weak, often below the background limit, and is mixed in the sea surface background clutter. In the current engineering, the energy collected by the system is increased by increasing the gain of the traditional photoelectric detector, increasing the photoelectric conversion efficiency of devices, increasing the aperture of an optical system and the like, but the target radiation information is still weak and is strongly interfered by sea clutter, so that the target is still difficult to detect.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides an on-orbit ocean dark and weak target optical image enhancement method, which enhances the characteristics of the ocean dark and weak targets and simultaneously inhibits sea clutter and detector noise, breaks through the limitation of computational complexity, is expected to realize the detection and identification of the on-satellite real-time ocean weak targets with large breadth, and has important application value.
The above purpose of the invention is mainly realized by the following technical scheme:
the on-orbit ocean dim target optical image enhancement method comprises the following steps:
establishing a mathematical model of an imaging system to obtain a relational expression between an acquired image of a detector and an algorithm recovery image and an atmospheric medium transmission image;
the constraint on the algorithm recovery image is minimum, and an atmospheric medium transmission image is obtained according to a mathematical model of an imaging system;
substituting the atmospheric medium transmission image into a mathematical model of an imaging system to obtain an optimized algorithm recovery image;
and extracting phase information and amplitude information from the optimized algorithm recovery image, and calculating to obtain the phase information in the enhanced scene graph.
In the above method for enhancing optical images of on-orbit marine dim targets, the mathematical model of the imaging system is established as follows:
I(x)＝(J(x)+B(x))×t(x)+A×(1-t(x))
wherein: i (x) acquiring an image for a detector; j (x) is an algorithm recovery image; t (x) is an atmospheric medium transmission image; b (x) is a sea surface background image; and A is the atmosphere radiance information on the sea surface.
In the on-orbit ocean dim target optical image enhancement method, the constraint on the algorithm recovery image is minimum, and the specific method for obtaining the atmospheric medium transmission image according to the mathematical model of the imaging system is as follows:
order:
the expression of the atmospheric medium transmission image t (x) is obtained as follows:
wherein: ρ is an adjustment constant.
In the above-described optical image enhancement method for the on-orbit ocean dim target, th = B (x) · 5%,
B(x)＝sign(λ)(|B(x)|-th)，|B(x)|≥th
in the on-orbit ocean dim target optical image enhancement method, the atmospheric medium transmission image is substituted into a mathematical model of an imaging system, and an expression of an optimized algorithm recovery image is obtained as follows;
wherein: j (x)' restoring the image for the optimized algorithm; t is t 0 The initial value of the transmission image of the atmospheric medium is shown.
In the optical image enhancement method for the on-orbit ocean dim target, the initial value t of the atmospheric medium transmission image 0 The values of (A) are as follows: 0.1<t 0 <0.3。
In the method for enhancing the optical image of the on-orbit ocean dim target, the specific method for extracting the phase information and the amplitude information from the optimized algorithm recovery image and calculating to obtain the phase information in the enhanced scene graph is as follows:
wherein: p is phase information in the enhanced scene graph; phi is a n (x) Is the extracted phase information; a. The n (x) Extracting amplitude information;is the average value of the phases; t is noise estimation; xi is a positive constant coefficient; w (x) is a weighting function.
In the above optical image enhancement method for the on-orbit marine dim target, the weighting function w (x) is expressed as:
wherein: c is a cut-off value, r is an adjustment factor,
the specific expression of S (x) is as follows:
wherein: a. The max (x) The maximum response amplitude of the filter at point x, N the filter dimension, and ξ a positive constant coefficient.
In the method for enhancing the optical image of the on-orbit ocean dim target, the value of the noise estimation T is 0-0.1.
In the method for enhancing the optical image of the on-orbit ocean dim target, the value of the adjustment factor r is 0-1.
Compared with the prior art, the invention has the following beneficial effects:
(1) Firstly, modeling imaging characteristics, then collecting weak information from the target by a detector, estimating scene information by a minimum constraint method, and extracting phase characteristics of the scene information so as to distinguish the target from sea surface background; the method solves the technical problem that the extremely weak targets of the ocean are difficult to detect in the traditional photoelectric detection method, enhances the characteristics of the dark and weak targets of the ocean, simultaneously inhibits sea clutter and detector noise, breaks through the limitation of calculation complexity, is expected to realize the detection and identification of the satellite real-time large-breadth weak targets of the ocean, and has important application value.
(2) The invention belongs to a novel space camera ocean weak target enhancing method, which is used for solving the problems that the existing on-orbit ocean weak target is poor in sensing capability and sea clutter is large and difficult to detect a target.
(3) The invention constructs a marine weak target enhancement method according to sea surface modulation characteristics and weak target distribution rules, which is a resolving method suitable for dark and weak targets under strong background clutter and can generate high-quality target intensity images under the condition of strong background noise.
Drawings
FIG. 1 is a flowchart of an on-orbit marine dim target optical image enhancement method of the present invention;
FIG. 2 is a simulation test result of the present invention; FIG. 2a is a trace emulation diagram; FIG. 2b is a background image of the sea; FIG. 2c is an optimized image; fig. 2d shows the detection of the striation information (enhanced phase information).
Detailed Description
The invention is described in further detail below with reference to the following figures and specific examples:
the invention constructs a marine weak target enhancement method according to sea surface modulation characteristics and weak target distribution rules, which is a resolving method suitable for dark and weak targets under strong background clutter and can generate high-quality target intensity images under the condition of strong background noise. The method firstly models the imaging characteristics, and then calculates the target information annihilated under clutter by using the received weak information from the target through an optimization method of minimization constraint. And then, the phase information is enhanced to obtain the horizontal stripe information of the trail target, thereby being beneficial to the high-level feature judgment of the subsequent target.
As shown in fig. 1, the method for enhancing an optical image of an on-orbit marine dark and weak target according to the present invention can suppress sea clutter and enhance target information, and the specific processing flow is as follows:
first, target and background feature analysis
1) Target characteristics: aiming at the current most important marine weak target detection, the geometric information of a target with weak radiation intensity needs to be extracted under a low-illumination background;
2) Background distribution characteristics: underwater target information is annihilated by an ocean background, and background clutter can be described as Poisson distribution according to probability distribution;
3) And (4) measuring the atmospheric characteristic parameters in the area.
Second, mathematical modeling
Establishing a mathematical model of an imaging system to obtain a relational expression between an acquired image of a detector and an algorithm recovery image and an atmospheric medium transmission image;
I(x)＝(J(x)+B(x))×t(x)+A×(1-t(x)) (1)
wherein: i (x) acquiring an image for a detector; j (x) is an algorithm recovery image; t (x) is an atmospheric medium transmission image; b (x) is a sea surface background image; and A is the atmosphere radiance information on the sea surface.
Thirdly, the constraint on the algorithm recovery image is minimum, and an atmospheric medium transmission image t (x) is obtained according to a mathematical model of an imaging system;
by minimizing constraints, let:
the expression of the atmospheric medium transmission image t (x) is obtained as follows:
wherein: ρ is an adjustment constant.
Setting th = B (x) · 5%,
B(x)＝sign(λ)(B(x)|-th)，|B(x)|≥th
step four, substituting the atmospheric medium transmission image t (x) into a mathematical model of an imaging system to obtain an optimized algorithm recovery image J (x)';
wherein: j (x)' restoring an image for the optimized algorithm; t is t 0 The initial value of the transmission image of the atmospheric medium is. Initial value t of atmospheric medium transmission image in the embodiment of the invention 0 The values of (A) are as follows: 0.1<t 0 <0.3。
Fifthly, extracting phase information phi from the restored image J (x)' of the optimized algorithm n (x) And amplitude information A n (x) And calculating to obtain the phase information P in the enhanced scene graph, wherein the specific method comprises the following steps:
wherein: p is phase information in the enhanced scene graph; phi is a n (x) Is the extracted phase information; a. The n (x) Extracting amplitude information;is the average value of the phases; t is noise estimation, and the value of T in the embodiment of the invention is 0-0.1; xi is a positive constant coefficient; w (x) is a weighting function.
The weighting function w (x) is expressed as:
wherein: c is a cut-off value, r is an adjusting factor, and the value of r in the embodiment of the invention is 0-1;
s (x) is a sigmoid function, and the specific expression is as follows:
wherein: a. The max (x) The maximum response amplitude of the filter at point x, N the filter scale, and ξ a positive constant coefficient.
The sixth step, simulation experiment
The experiment mainly simulates the marine weak target wake, and the simulation experiment result is shown in FIG. 2; the simulation of the weak ocean target is shown in fig. 2a, the image of the sea surface background is shown in fig. 2b, and the image recovered by the optimized algorithm after the processing by the method of the invention is shown in fig. 2 c. Therefore, the image quality of the image processed by the optimization method is greatly improved, and the contrast is enhanced. As shown in fig. 2d, the horizontal stripe information in the trail is effectively extracted through the enhanced phase information, and the high-level features of the target can be subsequently inverted through the horizontal stripe period.
Fig. 2a is an experimental simulation image, and it can be seen that under the condition of strong sea clutter, the modulation of the target on the sea surface is very weak, mainly because the geometric characteristics of the target are annihilated by the sea clutter and system noise. Fig. 2c shows that the texture of the target processed by the method of the present invention is clearer, the contrast between the contour information and the sea surface background is more obvious, and the noise and background noise in the original image are reduced. As can be seen from FIG. 2d, the method of the invention can effectively detect the trail horizontal striation information and can be used for inverting the high-level characteristics of the target.
Table 1 below shows the comparison between the conventional treatment method and the method of the present invention. Table 1 shows that the method of the present invention can quantitatively determine that, compared with the conventional method, the method of the present invention has higher indexes such as the signal-to-noise ratio of the image, the contrast, the entropy of the information, the Euclidean distance measure, etc., which are better than those of the conventional method, and can effectively increase the image quality of the image after being processed, and enhance the effective information of the target in the image, which is beneficial to the subsequent image judgment and target identification.
TABLE 1 Objective evaluation results of image quality
The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are also within the scope of the present invention.
The invention has not been described in detail in part of the common general knowledge of those skilled in the art.
Claims (10)
1. The on-orbit ocean dim target optical image enhancement method is characterized by comprising the following steps of:
establishing a mathematical model of an imaging system to obtain a relational expression between an acquired image of a detector and an algorithm recovery image and an atmospheric medium transmission image;
the constraint on the algorithm recovery image is minimum, and an atmospheric medium transmission image is obtained according to a mathematical model of an imaging system;
substituting the atmospheric medium transmission image into a mathematical model of an imaging system to obtain an optimized algorithm recovery image;
and extracting phase information and amplitude information from the optimized algorithm recovery image, and calculating to obtain the phase information in the enhanced scene graph.
2. The on-orbit marine dim target optical image enhancement method according to claim 1, characterized in that: the mathematical model of the imaging system was established as follows:
I(x)＝(J(x)+B(x))×t(x)+A×(1-t(x))
wherein: i (x) acquiring an image for a detector; j (x) is an algorithm recovery image; t (x) is an atmospheric medium transmission image; b (x) is a sea surface background image; and A is the atmosphere radiance information on the sea surface.
3. The on-orbit marine dim target optical image enhancement method according to claim 2, characterized in that: the method for obtaining the atmospheric medium transmission image according to the mathematical model of the imaging system has the following concrete steps:
order:
the expression of the atmospheric medium transmission image t (x) is obtained as follows:
wherein: ρ is an adjustment constant.
4. The on-orbit marine dim target optical image enhancement method according to claim 3, characterized in that: setting th = B (x) · 5%,
B(x)＝sign(λ)(|B(x)|-th)，|B(x)|≥th
5. the on-orbit marine dim target optical image enhancement method according to one of claims 1 to 4, characterized in that: substituting the atmospheric medium transmission image into a mathematical model of an imaging system to obtain an expression of an optimized algorithm recovery image as follows;
wherein: j (x)' restoring the image for the optimized algorithm; t is t 0 The initial value of the transmission image of the atmospheric medium is shown.
6. The on-orbit marine dim target optical image enhancement method according to claim 5, characterized in that: initial value t of atmospheric medium transmission image 0 The values of (A) are as follows: 0.1<t 0 <0.3。
7. The on-orbit marine dim target optical image enhancement method according to claim 5, characterized in that: the specific method for extracting the phase information and the amplitude information from the optimized algorithm recovery image and calculating to obtain the phase information in the enhanced scene graph is as follows:
wherein: p is phase information in the enhanced scene graph; phi is a n (x) Is the extracted phase information; a. The n (x) Is composed ofExtracted amplitude information;is the average value of the phases; t is noise estimation; xi is a positive constant coefficient; w (x) is a weighting function.
8. The on-orbit marine dim target optical image enhancement method according to claim 7, characterized in that: the weighting function w (x) is expressed as:
wherein: c is a cut-off value, r is an adjustment factor,
the specific expression of S (x) is as follows:
wherein: a. The max (x) The maximum response amplitude of the filter at point x, N the filter dimension, and ξ a positive constant coefficient.
9. The on-orbit marine dim target optical image enhancement method according to claim 7 or 8, characterized in that: the noise estimate T takes a value of 0 to 0.1.
10. The on-orbit marine dim target optical image enhancement method according to claim 8, characterized in that: the value of the adjusting factor r is 0-1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711193771.7A CN107833195B (en) | 2017-11-24 | 2017-11-24 | On-orbit ocean dim target optical image enhancement method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711193771.7A CN107833195B (en) | 2017-11-24 | 2017-11-24 | On-orbit ocean dim target optical image enhancement method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107833195A true CN107833195A (en) | 2018-03-23 |
| CN107833195B CN107833195B (en) | 2020-10-23 |
Family
ID=61652594
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711193771.7A Active CN107833195B (en) | 2017-11-24 | 2017-11-24 | On-orbit ocean dim target optical image enhancement method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107833195B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114202491A (en) * | 2021-12-08 | 2022-03-18 | 深圳市研润科技有限公司 | Method and system for enhancing optical image |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102646267A (en) * | 2011-12-12 | 2012-08-22 | 中国科学院深圳先进技术研究院 | Degraded image restoration method and system |
| CN105761227A (en) * | 2016-03-04 | 2016-07-13 | 天津大学 | Underwater image enhancement method based on dark channel prior algorithm and white balance |
| CN105913390A (en) * | 2016-04-07 | 2016-08-31 | 潍坊学院 | Image defogging method and system |
| CN106204494A (en) * | 2016-07-15 | 2016-12-07 | 潍坊学院 | A kind of image defogging method comprising large area sky areas and system |
| KR101705536B1 (en) * | 2015-10-08 | 2017-02-10 | 목포해양대학교 산학협력단 | A fog removing method based on camera image |
-
2017
- 2017-11-24 CN CN201711193771.7A patent/CN107833195B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102646267A (en) * | 2011-12-12 | 2012-08-22 | 中国科学院深圳先进技术研究院 | Degraded image restoration method and system |
| KR101705536B1 (en) * | 2015-10-08 | 2017-02-10 | 목포해양대학교 산학협력단 | A fog removing method based on camera image |
| CN105761227A (en) * | 2016-03-04 | 2016-07-13 | 天津大学 | Underwater image enhancement method based on dark channel prior algorithm and white balance |
| CN105913390A (en) * | 2016-04-07 | 2016-08-31 | 潍坊学院 | Image defogging method and system |
| CN106204494A (en) * | 2016-07-15 | 2016-12-07 | 潍坊学院 | A kind of image defogging method comprising large area sky areas and system |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114202491A (en) * | 2021-12-08 | 2022-03-18 | 深圳市研润科技有限公司 | Method and system for enhancing optical image |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107833195B (en) | 2020-10-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108492274B (en) | Long-wave infrared polarization feature extraction and fusion image enhancement method | |
| Deng et al. | Infrared moving point target detection based on spatial–temporal local contrast filter | |
| Gershikov et al. | Horizon line detection in marine images: which method to choose? | |
| CN109447073B (en) | Infrared weak and small target detection method based on tensor robust principal component analysis | |
| CN103761731A (en) | Small infrared aerial target detection method based on non-downsampling contourlet transformation | |
| CN105184804B (en) | Small targets detection in sea clutter method based on Airborne IR camera Aerial Images | |
| CN106780385B (en) | A kind of fog-degraded image clarification method based on turbulent flow infra-red radiation model | |
| CN107392095A (en) | A kind of small IR targets detection algorithm based on mask image | |
| Wang et al. | A robust infrared dim target detection method based on template filtering and saliency extraction | |
| CN105469428B (en) | A kind of detection method of small target based on morphologic filtering and SVD | |
| Li et al. | A small target detection algorithm in infrared image by combining multi-response fusion and local contrast enhancement | |
| CN111353496A (en) | Real-time detection method for infrared small and weak target | |
| Li et al. | DIM moving target detection using spatio-temporal anomaly detection for hyperspectral image sequences | |
| Liu et al. | Moving dim and small target detection in multiframe infrared sequence with low SCR based on temporal profile similarity | |
| CN114758219A (en) | Trace identification method based on spectral data and infrared temperature data fusion | |
| CN107833195B (en) | On-orbit ocean dim target optical image enhancement method | |
| Hwang et al. | An efficient ship detection method for KOMPSAT-5 synthetic aperture radar imagery based on adaptive filtering approach | |
| Balasubramanian et al. | Utilization of robust video processing techniques to aid efficient object detection and tracking | |
| CN109285148B (en) | Infrared weak and small target detection method based on heavily weighted low rank and enhanced sparsity | |
| CN105551029A (en) | Multi-spectral remote sensing image-based ship detection method | |
| Weihua et al. | A real-time detection algorithm for unmanned aerial vehicle target in infrared search system | |
| CN108537807A (en) | One kind enhancing detection method based on the improved edge of No. four satellite images of high score | |
| Makki et al. | Classification algorithms for landmine detection using hyperspectral imaging | |
| CN102682296B (en) | Self-adaption estimating method of size of infrared small dim target under complicated background condition | |
| Yoon et al. | Preliminary study for detecting of ocean wave parameters using CCD images |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |